Windows 10 for phones is on the way, at least in preview form. Tonight, Microsoft began laying more groundwork for the Technical Preview by updating their Phone Insider app. Originally found on the Store a few weeks ago, the Insider program will let people download early builds of Windows 10 to their phones before general release.
The major change to the app is the name to Windows Insider, matching the name of the desktop preview program. Besides the previous domain account support, there is also the ability to now log in the Insider service using your Microsoft Account.